Core lowering device



June 12, 1951 R. l. TERRY, JR

CORE LOWERING DEVICE 5 Sheets-Sheet 1 Filed June 29, 1949 mmvrox. R BERT 1. TERRYJR ATTORNEY June 12, 1951 R. l. TERRY, JR 2,556,404

CORE LOWERING DEVICE Filed June 29, 1949 3 Sheets-Sheet 2 ROBERT 1. TERRY an.

ATTORNEY u 1951 R. 1. TERRY, JR 2,556,404

CORE LOWERING DEVICE Filed June 29, I949 s Sheets-Sheet s IN V EN TOR.

ROBERT 1. TERRY R- BY V 4 .31

10 ATTORNEY Patented June 12, 1951 CORE LOWERING DEVICE Robert I. Terry, J12, Indianapolis, Ind, assignor to Gulf Oil Corporation, Pittsburgh, Pa.', a corporation of Pennsylvania Application June 29, 1949, Serial No. 102,099

3 Claims.

This invention relates to a core lowering device and more particularly to an improved device for gripping a rock core as the same is being lowered from the core barrel, the device being suspended from the lower end of the core barrel.

During the drilling of Wells and particularly oil wells, it is often desirable to take for analysis formation samples at the depth which has been reached during drilling. For this purpose, a rotary coring device is usually employed. When the barrel of the coring device has been filled with a sample taken at the desired depth, it is removed from the drill hole. Portions of the core are then taken from the core barrel, labeled in sequence of their removal and set aside for future analysis. During the removal of the portions of core from the core barrel, some means is necessary to grip the main body of the core and to prevent its slipping from said core barrel.

The prior art employed a device for this purpose which comprises an adjustable collar for gripping the core barrel and a pair of scissor tongs suspended therefrom by means of chains. The core barrel, on which was mounted the adjustable collar means, was raised from the derrick floor, thus exposing a section of the core contained in the core barrel. Said core was then gripped by means of the scissor tongs while a portion of the core below said tongs was sawed or. broken 01f.

The principal object of my invention is to provide a positive grip on the core with less dependence on the. strength of the operator.

Another object is to provide an improved device. which may be employed with either the outer core barrel or the inner tube contained therein.

Ajfurther object is to provide a pair of jaws having core gripping faces which will cut through a thick mud cake on the core and enable the operator to grip said core tightly.

A still further object is to provide an improved device which will lessen the accident hazard to an operator working on a slippery derrick floor, which, hazard results from the slipping of the core from the core barrel.

Another object is to provide an improved gripping means for cores of greater lengths and weights now obtainable from the use of diamond bits.

Another object is to provide a device which will lessen the possibility of scrambling of the core.

Other objects will appear hereinafter.

These and other objects are accomplished by my invention, which comprises means for gripping the core barrel, a pair of jaw means pivotally mounted on and dependent from said core barrel gripping means, and toggle means for opening or closing said jaw means.

In the drawings similar characters of reference indicate corresponding parts in the several views:

Figure l is a top plan View of the device;

Figure 2 is a side elevation of the apparatus;

Figure 3 is an end elevation thereof; and

Figure 4 is an isometric view of a sin le member of the jaw means:

Figure 5 is an isometric view of a jaw with associated actuating linkage and with means for holding the jaw locked in gripping position;

Figure 6 is a detail view of the locking dog shown in Figure 5.

Referring to the drawings in detail, I denotes an adjustable collar hinged at 2 to enable it to be opened for clamping around the core barrel. Bolt 3 is provided for tightening the collar around the core barrel. Numerals d. and 5 refer to a pair of bifurcated arms extending from opposite sides of the collar. Passing through arms 4 and 5 are suspension pins 8 and l, on which jaw elements 3 and 8 are pivotally and remcvably mounted by means of J-slots Illand II adjacent the upper ends of the shank portions of the respective jaw elements. Numerals i2 and [3 denote the grooved gripping faces of the jaw elements 3 and 9. Numeral M denotes a lever for opening and closing the jaws. Lever M flares at its lower end into parallel members 22 and 2.3 which are pivotally attached to jaw 9 by means of a pin [5 which passes entirely through said jaw. Links l6 and I1 perform the function of connecting lever M and jaw 8. Links [5 and H are pivotally attached at one end to jaw 8 by means of pin l9 which passes entirely through jaw 8. Links l5 and I1 are pivotally attached to lever I4 by means of removable pin [8 which passes entirely through said lever. and 2| on the jaw 9 (shown clearly in Figure 4) extend between the bifurcations of the operating lever and afford a long bearing surface for the pin I5 to which the lever and connecting links are connected, thereby allowing links I5 and H to clear the gripping faces l2 and I3 and keeping the gripping faces accurately opposed to each other.

In case it is desired to lock the jaws in gripping positions so that the. operator may release the lever I4 and detach a projecting portion of core or perform other duties requiring freedom to use his hands, some locking means may be provided Shoulders 2e such as the pawl and ratchet shown in Figures 5 and 6. As there shown the pawl 24 is pivotally mounted at the point where the lever forks so that in being swung forwardly it engages the ratchet teeth 25 which are formed in the shank of jaw element 9. The forward swing of the pawl is limited by a flattened surface 26 which, in extreme position of the pawl, engages the surface of the lever so that the pawl is prevented from failing to an inoperative position where it will not engage the ratchet teeth. When not in use the pawl may be swung backward against the lever.

Various other locking means are within the purview of my invention, such as a chain anchored at one end to the derrick floor, which may be pulled taut and engaged in a notch in the end of the lever. Another proposed locking means which is contemplated is a ratchet extending from the shank of the nearest jaw past the lever and engaged by a lug mounted on the lever, the ratchet being pivotally mounted so that it may be moved into or out of locking engagement with the lug. Still another proposed looking means is a C-shaped clamp which directly engages the opposing jaws and prevents their accidental separation. In view of the simplicity of these various modifications it is not deemed necessary to illustrate them individually, it being suflicient for an understanding of my invention to illustrate the one form shown in Figures 5 and 6.

The operation of my device is as follows: The core barrel is raised from the drill hole and its lower end rested on the derrick floor. The core retainer which retains the core in said core barrel is removed from the bottom of said core barrel, so that the core contained therein may be lowered therefrom. If desired, the links it and H may be disconnected from lever I by removing removable pin [8, thereby allowing the jaws to swing freely and to be opened as widely as may be desired. The jaws are spread Widely and collar l is opened and clamped around the core barrel at a height which will allow gripping faces l2 and I3 to clear the lower end of said core barrel. The core barrel may be conveniently provided with a horizontal annular groove to aid the gripping of the core barrel by the collar. The core barrel having my invention clamped thereto is then hoisted, whereby a portion of the core is exposed. When a convenient amount of the core contained in said core barrel is exposed, links l6 and I! are attached to lever [4 by replacing pin [8. The core is then gripped by gripping faces [2 and 13 by applying a downward pressure to lever [4. The downward pressure on lever l4 imposes a pulling force on jaw 8 and a thrusting force on jaw 9, thus enabling the core to be gripped and, if desired, the jaws may be locked in this position. A portion of the core extending below gripping faces l2 and i3 is then sawed or broken off from the main body of the core. The core barrel with my improved device clamped thereto is again hoisted slightly so that the core sample resting on the derrick floor may be removed. The core barrel and my device are then lowered to the derrick floor, the jaws released, and the process is repeated.

At certain times during the sampling process when the core is tightly compacted or jammed in the core barrel, it is necessary to bounce said core barrel on the derrick floor to loosen the core. When this is necessary, jaws 8 and 9 should be removed from collar I. They may be conveniently detached by slipping J-slots l0 and II over pins 6 and I. By making jaws 8 and 9 easily removable it is not necessary to remove the entire device from the core barrel during the bouncing of the core barrel, but merely jaws 8 and 9, thus effecting a saving in time. Sufiicient clearance should be allowed between the inner edge of pins 6 and 1 and outer circumference of collar 1 to enable the jaws to be removed.

In the case of a jammed core, it is often necessary to remove from the outer core barrel the inner tube contained therein. For the clamping of said inner tube, my device also contemplates the use of a second collar, not shown in the drawings (since it is of similar construction to the first described collar) whose inner diameter corresponds to the outer diameter of said inner tube. Jaws 8 and 9 may likewise be suspended from the suspension pins of this collar since in both collars the distance between suspension pins 6 and I is identical.

In the claims, core barrel is intended to include both the outer core barrel and the inner tube thereof. '1

As another modification of my device, I may use a single lever and a single connecting link connected at only one side of my device.

Furthermore, jaws 8 and 9 need not necessarily be inwardly curved since straight jaws means could also be used, but less satisfactorily.

While my device has been described as useful principally with the cores of longer lengths and greater weights obtainable from the use of diamond bits, my improved device may also be used with other types of bits.

The operation of the prior art device described above was directly dependent upon the strength of the operator. My invention is superior thereto since the strength of the operator is immaterial. One may apply his entire weight to the lever as desired.

The present day processes of rotary coring using improved cutting bits such as diamond bits have resulted in the higher recovery of core in greater lengths and weights. Often because of a thick mud cake on the core and/or because of the great weight of the core, the operator is unable to grip said core tightly enough with the previously employed scissor tongs, whereupon the core slips from the barrel, endangering the operator and breaking or scrambling the core. It may be seen that the prior art device is not only hazardous but also at times ineffective to produce efil'cient and correct sampling technique. My invention overcomes these defects by not only eliminating the hazards attendant to the operation of the previously employed device but also by preventing scrambling of the core and by enabling true samples of representative depths to be taken.

My device is also superior to the prior art device in that its flexibility is increased. In bouncing the core barrel to loo-sen a jammed core the prior art device necessarily was detached from the core barrel. My improved device renders this unnecessary since the gripping jaws may conveniently be removed at any time during the core removal process.

From the foregoing description it will be readily seen that I have produced such a device as substantially fulfills the objects of the invention as set forth herein.

While this specification sets forth in detail the present and preferred construction of the device, still in practice deviations from such detail may be resorted to as do not form a departure from the invention as defined by the appended claims.

I claim:

1. A tool for gripping a rock core as the same is lowered from a core barrel, comprising a pair of jaw elements each having a gripping surface and a shank portion, means attachable to the core barrel for suspending said jaw elements by the shank portions thereof, with the gripping surfaces in position to engage a portion of core protruding from the core barrel, a lever pivoted at one end to one of said jaw elements, a pawl carried by said lever adapted to be swung into engagement with the shank portion of the adjacent jaw element, ratchet teeth formed in the shank of the adjacent jaw element, and a link extending between an intermediate portion of said lever and the other said jaw element, whereby as the lever is moved about its pivot the jaws open and close upon the protruding core.

2. A tool for gripping a rock core as the same is lowered from a core barrel, comprising a clamping ring detachably secured to a core barrel, bifurcated arms projecting from said ring, each arm having a pin bridging the bifurcations thereof, a pair of generally L-shaped jaw elements having hook-like upper ends engaging said pins for suspending said jaw elements from said collar, a hand lever pivoted to one jaw element, a connecting link extending from the other jaw element to a point between the ends of said hand lever, whereby as the hand lever is swung to jaw clamping position the pivots of said lever and link approach straight-line position thereby increasing the gripping pressure under moderate applied force.

3. A tool for gripping rock cores as the same are lowered from a core barrel, comprising a clamping ring detachably secured to a core barrel, bifurcated arms projecting from said ring, each arm having a pin bridging the bifurcations thereof, a pair of generally L-shaped jaw elements mounted for suspension from said pins with the short arms thereof inwardly directed and terminating in arcuate gripping jaws, shoulders projecting on each side of the short arms of said jaw elements and forming a wide rearward extension of each jaw substantially coextensive in length with the short arm of the jaw element, a bifurcated hand lever embracing the shoulders of one jaw element and provided with means for pivotally' securing the same thereto, parallel conneeting links pivotally mounted on said hand lever and extending to the opposed jaw element on each side of the shoulders thereof, and means for pivotally attaching said connecting links to said opposed jaw element.

ROBERT I. TERRY, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,552,062 Krell Sept. 1, 1925 2,049,580 Wright Aug. 4, 1936 

